The German-made Leopards were at the centre of a public spat earlier this year after Belgian Defence Minister Ludivine Dedonder said the government had explored buying back tanks to send to Ukraine but had been quoted unreasonable prices.
Freddy Versluys, CEO of defence company OIP Land Systems, bought the tanks from the Belgian government more than five years ago.
The German Defence Ministry had no immediate comment.
Several of Kyiv's Western allies agreed earlier this year to send modern Leopard 2 tanks to Ukraine and also to send older Leopard 1 models.
A spokesperson for the Belgian defence ministry declined to comment on the sale of the tanks.
Persons:
Freddy Versluys, Read, Ludivine Dedonder, Germany's, Versluys, Krauss, Andrew Gray, Christoph Steitz, Sabine Siebold, Jonathan Oatis, Alex Richardson
Organizations:
OIP, Systems, Belgian, Leopards, Belgian Defence, Reuters, Rheinmetall, LinkedIn, NATO, German Defence Ministry, Maffei, Thomson
Locations:
Belgian, Ukraine, Wallonia, Germany, Tournais, Belgium, BRUSSELS, Vilnius